A series of reduced-scale experiments were carried out in order to investigate thermal behaviors of window flame, which exposes the upper floors as well as the adjacent buildings to potential * Q′

A model for predicting the trajectory of window flame ejected from a fire compartment was formulated incorporating the effect of wall above the opening. Based on the observation in the reduced scale experiments, window flames were divided into following categories with regard to its trajectory configuration: the flow which ascends almost vertically up after ejection maintaining a certain separation from the wall; and the flow which ascends upward after ejection and gradually approaches to the wall in the downstream. In the model, trajectories of these flows were approximated by cubic polynomials whose coefficients were given as functions of a dimensionless parameter * F. The parameter * F was derived from the conservation equation of momentum which incorporates the effect of pressure gradient across the ascending flows. Critical condition for the occurrence of flow attachment was described as a proportion of the maximum separation from the wall versus the opening width. Trajectories predicted by the proposed model were then compared with the measurement data which indicated reasonable agreements.

To clarify the self-extinguishing conditions and the rate of char oxidation of glued laminated larch timber materials, heating experiments were carried out using a cone calorimeter. Larch specimens were heated to be ignited and burn. After the char layer was formed at heated surface, surface flame was extinguished itself. Glowing char oxidation and smoldering combustion were observed under the heating flux of zero to 50kW/m 2 . Char oxidation started at temperatures above 366 o C and stopped at 166 to 360 o C. The mass loss rate was measured by a load cell, while surface shrinkage rate and surface temperatures were measured simultaneously using laser sensors.As the heating rate decreased, mass loss rate and surface temperatures were decreased. The rate of char oxidation reaction was estimated by three methods of heat conservation of whole specimen, of heated surface and direct measurement of mass loss rate. The results agreed fairly well and the rate equation was established in the form of Arrhenius type rate equation.

No abstract

In performance-based fire safety design of buildings, design fires are assumed based on relatively coarse information of potential combustible objects described by the object name, weight, size and constituent materials. The fire effect is calculated by using assumed design heat release rate (HRR) to judge appropriateness of fire safety provisions. For this purpose, a simple estimation method to estimate design HRR curve (full time history of HRR) was developed. The method is based on summary of available experimental datasets of various combustibles, which were categorized into groups by their names and constituent materials. As a nature of categorized groups, there are two types of variations of HRR characteristics within each category group. One type is that the object size is almost constant within each category group. For this type, HRR curves are simply averaged over the available datasets in order to obtain the characteristic design HRR curve. The method was applied to chairs and sofas. The other type is that the object size varies within each category group. To develop size-dependent HRR curves, rates of fire growth and decay were averaged over datasets in the group. Maximum HRR and total heat release (THR) were correlated with surface area and weight, respectively.The method was applied to Christmas trees. By using the proposed methods, it is possible to establish a simple formula to represent full HRR diagrams by their category names.